Oil burner



` Sept, 26,1944. T, MGEL 2,359,049

on. summa' Filed Feb. 10. `1.942

ATTORNEYS flows continuously Patented Sept. 26, 944

UNITED sTATEs PATENT oFFlcE ongm Theodore Natel, Brooklyn, N Y.

Application February No. 430,19

2 Claims.

'This invention relates to an improvement in atomizing type oil burners.

With the usual types of fuel oil burners for marine and stationary power plant boilers for the generation of steam, it is customary to lower the viscosity of the heavy fuel oil used'. to permit of its atomization by the release of pressure which occurs when the oil flows from the orifice of the oil atomizing nozzle. The oil flows from the nozzle into the ilrebox as a hollow, conical, diverging stream of atomized oil. Combustion air, supplied either by forced, induced or natural draft, enters the flrebox through the same flrebox opening as the oil, and flows forward through the ilrebox opening with a rotary motion. This rotary motion of the airis produced by various types of air register vanes so designed as torotate the combustion air as it flows past the vanes. After flowing forward past the flrebox opening into the iirebox the air ows off tangentially due to its rotational motion, flowing away from the ignited atomized oil. More air is required, there-i fore, to produce smokeless combustion than the theoretical quantity of air required by the oil, and consequently heat losses are created due to lowerng the temperature of the combustion prod' ucts by this excess air.

In the practice of my invention I eect a very radical departure from this prior practice in that rotation of the combustion air is prevented and the air stream instead of flowing off tangentially away from the diverging stream of ignited atomized oil is caused to converge across the path of this stream.

In the oil burners constituting the subject matter of the present invention, the air register vanes above referred to are eliminated and provision is made for preventing rotation of the combustion air. In addition my improved burner is provided with a windshield which functions to Provide a wind-protected zone into which the oil is atomized and within which the oil is ignited. Through this zone a substantially reduced quantity of air is permitted to flow at a velocity lower than the rate of flame propagation.

This air is ignition air, being sufficient in quantity to support ignition of the atomized oil, and it through the wind-protected Zone.

The oil nozzle in my improved burner is con-` siderably retracted from the entrance to the rebox and is no longer directly at this entrance, as in prior practice, while the major volume of air necessary for combustion of the ignited atomized oil is so deflected that the combustion air stream converges across the path of the diverging stream of ignited atomized oil after the ignited oil has passed through the wind-protected zone above referred to.

Ignition of the globules of atomized oil effects surface combustion, forming a gaseous film surrounding each globule of liquid flowing through the wind-protected zone, and these individual spheres of ignited oil with their surrounding gaseous films are projected into the converging stream of combustion air. The velocity of the converging stream of combustion air is such that the individual, gas-surrounded spheres of ignited oil are forced from their projected path of divergent flow so that they are carried along within the converging stream of combustion air flowing toward the flrebox opening, thereby increasing the rate of combustion and liberation of heat, which vaporizes the liquid spheres, forming a mixture of oil vapor and air and producing premixed gaseous flame combustion within the furnace.

This is a clear distinction over the prior practice of combustion of a diverging stream of ignited atomized oil flowing intoV the furnace along with a stream of rotating air which flows of! tangentially, as the result of its rotating motion. as a diverging stream after passing the entrance into the flrebox.

The accompanying-drawing illustrates in sectional elevation one embodiment of my invention,

Fig. 1 being a sectional side elevational viewv of however, the nozzle and flame cone assembly are retracted a lsubstantial distance from the opening into the ilrebox and a windshield 8 is interposed between the burner nozzle and the wind-boxin the path of the stream of combustion air. This windshield, as illustrated, takes the form of a sleeve surrounding the nozzle and flame cone and projecting beyond the oil atomizing nozzle 4.

-When the combustion air flowing forward into the flrebox opening tends to rotate a series of fixed vanes In are disposed about the windshield 8. These vanes are so shaped as to prevent ro tation of the air as it flows forward from the wind-box or air tube I6 into the furnace.

. Adjustably mounted Within the Shield 8 is t?.l

v with natural draft.

2B designates a forced draft air conduit equipped with damper 22 for control of the quantity of air passing therethrough. I p

24 designates a plurality of air doors in the burner front, which are opened when it is desired to operate the system under natural draft or induced draft.

In operation, ignition air flows into the outer end of the windshield 8. The volume of this air is lmuch less than that necessary for combustion of the oil. The velocity of this smaller volume of ignition air fiowing'- through the wind-shielded zone is lower than the rate of Vame propagation of theV oil, consequently after ignition has been established, the wind-protected zone forms a permanent ignition zone.

It will be understood that ignition of the-atomized globules of oil ejected from the nozzle 4 will effect surface combustion forming a gaseous nlm surrounding each globule of liquid while ilowingthrough the wind-shielded zone provided by the shield 8. These individual spheres of ignited oil as they pass out of the wind-shielded zone are projected into the advancing stream of non-rotating combustion air which converges toward the long axis of the burner due to the inwardly tapered or convergent throat Il of the sleeve I6. The velocity of this converging stream of combustion air is sufficient to force 'the ignited gaseous spheres of oil from their projected path of divergent flow so that they are necessarily carried along within the convergent stream of combustion air. This speeds up combustion and liberation of heat, eifectlng ash vaporization of the oil and forming a mixture of oil vapor and air, so as to produce a premixed gaseous flame within the furnace with less air dilution for producing smokeless combustion than the oil atomizer, a` combustion air tube surrounding and spaced from the atomizer and extending forwardly of the burner beyond-the forward :and of the atomizer, the wall of said air tube at its inner end being sloped inwardly to deflect the combustion air toward the Yburner axis; an annulus with-V in the said air tube concentric with the atomizer and extending beyond the plane of the base of the inwardly sloping wall portion of the air tube but terminating short of said wall, said air tube and annulus providing for the passage of combustion airv along the air tube axially of the burner and then inwardly toward the burner axis. iins on the exterior of said annulus extending in the direction of air ow through the air tube and parallel to the axis of the burner, said dns terminating beyond the plane of the base of the inwardly sloping portion of the air tube, to prevent rotation of the combustion air, the said annulus `at its outer end and said combustion air tube being provided with air inlets for the admission of ignition air to the outer end of said annulus and for the admission of combustion air to thecombustion air tube, the last mentioned air being deilected inwardly ofthe burner into the ignited oil discharging from said annulus, and dampers [or controllingthe admission of air to said inlets.

2. An oil burner comprising in combination an oil atomizer, a combustion air/tube surrounding and spaced from the atomizer and extending forwardly of the burner beyond the forward end of the atomizer, the wall of said air tube st its necessary excess air required for smokeless combustion of oil by conventional oil burner practice.

It is to be understood that my invention comprehends the provision of a nest of burners with.

a single wind-box feed to all burners, each burner being equipped with a windshield providing a wind-protected zone.

It is to be understood that changes may 'be made in the details of construction and arrange-I inner end being sloped inwardly to deflect the combustion air toward the burner axis, an annulus within the said air tube concentric with the atomizer and extending beyond the plane of the base of the inwardly sloping lwall portion of the air tube but terminating short of said wall, s'aid air tube and annulus providing for the` passage of combustion air along the air tube axially of the burner and then inwardly toward the burneraxis, fins on the exterior of said annulus extending in the direction of air ow through the air tube and parallel to the axis of the burner, said fins terminating beyond the plane of the base of the inwardly sloping portion of the air tube, to prevent rotation of the combustion air, a sleeve tting within and positioned at the inner end of said annulus, means for adjusting the Y same axially of the burner thereby to vary the eiective length ofthe annulus, the said annulus at its outer end and said combustion air tube being provided with air inlets for admitting ignition air to said annulus and .for the admission of combustion air `between the annulus and combustion air tube, and dampers forcontrolling the admission of air to said inlets.

'Innoponn NAGEL. 

